KSEF R&D Excellence: Evaluating the Severity of Spinal Cord Injury with Manganese-enhanced Magnetic Resonance Imaging

This project will investigate the application of a novel form of an exogenous contrast agent to enhance magnetic resonance images of spinal cord injury. The divalent cation, manganese (Mn 2+)is known to enter cells throu~h the same voltage gated channels as Ca2+.When neurons are activated in the presence of Mn + it will enter the neuron and reside there for periods extending several days. Unlike, Ca2+,Mn2+is strongly paramagnetic and will enhance the signal from MR images. We propose to investigate this phenomena in spinal cord injured rats and to determine if the extent of enhancement varies rostral and caudal to the injury. We hypothesize that the enhancement caudal to the site of the spinal cord injury will be less than that rostral. We hypothesize this because the extent of neural activation caudal to the spinal cord injury will be less than that rostral. Further, we hypothesize that the extent of enhancement of the MR images will depend upon the rat using its hind legs while the manganese is available. Thus we hypothesize that the degree of enhancement in both the rostral and caudal sections of the ~inal cord will be greater when the animal uses it hind limbs to move about while the manganese is infused. This project will explore the potential information about spinal cord injury which can be obtained using manganese as a contrast agent. The technique will open up new areas of research into changes in the spinal cord which accompany recovery of locomotor ability. The great advantage of this technique is that it visualizes changes in spinal cord function while the animal is alive. Thus, the technique could be used to visualize and objectively measure the changes occuning in recovery from spinal cord injury. The technique would likely be useful in differentiating the effects of therapeutic approaches to diminishing the extent or severity of the secondary injury or recovery following rehabilitation strategies.